An investigation into how a man fell overboard from a Rigid Inflatable Boat in Cork Harbour and was seriously injured has concluded that the boat's kill cord was not working properly.

Owen Corkery, an experienced motor boat enthusiast and sole occupant of the RIB, sustained serious injuries to his head and back and lost his left arm in the accident, which happened on 9 June 2012.

The Marine Casualty Investigation Board's report found that Mr Corkery had been thrown from the boat as he altered course to pass under the bridge at Haulbowline and sustained his injuries when the boat continued to turn in a circle in the water.

He had been standing and not sitting in the pilot seat, and was not wearing shoes which, investigators noted, would have aided his grip.

The report concluded that Mr Corkery would not have sustained his injuries if the boat's kill cord was working and that he was aware that the system was malfunctioning.

They recommended that, as an essential part of safety equipment, a kill cord should be checked regularly.

As a small throttle shift or turn of the wheel can profoundly affect centrifugal and G-forces, the helm of a high-speed craft should always remain seated, even at low speed.